Dimpling tool



A. A. SHYMANSKI 2,944,581

YDIMPLING TOOL July 12, 1960 Filed Sept. 4, 1956 2 Sheets-Sheet 1INVENTOR ADOLPH A. SHYMANSKI p Patented July 12,, 1966 DIMPLING TOOL IAdolph A. Shymanski,- Los Angeles, Calif., assignor to ZephyrManufacturing (10., Inglewood, Calih, a partnership Filed Sept. 4, 1956,Ser. No. 607,621 3 Claims. ((1153-41) This invention has to do withfluid-actuated tools for applying pressure in oppositedirections to awork piece, such as, for instance, a metal sheet, and while the"invention is adaptable for other uses, it finds its chief utility as atool for embossing, countersinks or dimples in such work sheets aroundthe holes provided therein for the reception of rivets and otherfasteners,

One of the objects of my invention is to provide a device of thischaracter which is so designed and constructed as to be capable of beingmade relatively small, self contained, of lightweight and portable tothe extent that it is adaptable for use as a hand tool.

Another object of. the invention is to provide a dimpl'ing tool. whichprovides substantial leverage advantages capable of reducing to aminimum the ainount'of fluid pressure required to supply thenecessary'operating pressures.

A more specific object is to provide a d'impling tool wherein a gun-typebody member presents a metal fortning surface through which afluid-actuated plunger projects and is reciprocable, the outer end ofthe plunger releasably carrying a second metal forming member, so that awork sheet may be placed between the forming members, the formingmembers then being moved towards each other by the fluid pressureagainst opposite surfaces of the sheet to emboss the sheet around afastener-receiving perforation therein.

My invention additionally includes as objects other novel structuralfeatures which enable the attainment of the before-mentioned,and-includes other objects and advantages, all of which will becomereadily apparent from the ensuing description.

While 'I shall point out in the appended claims the features which Ibelieve to be new, I shall now, for the purpose of rendering myinvention clearly understandable to those skilled in this art, describea presently preferred embodiment thereof for which purpose I shall.refer to the accompanying drawings wherein,

Fig. 1 is a side elevational view of the pneumatic gun; M Fig. 2 is anend elevational view taken on line' 2'--2' of Fig. 1;

Fig. 3 is an enlarged section taken on line 3--3 of Fig. 2, showing theparts in their idle position;

Fig. 4 is a fragmentary sectional view showing the parts in the positionwhich they occupy at the end of the power stroke of the piston;

Figs. 5 and 6 are enlarged sectional views taken respectively on lines5-5 and 6-6 of. Fig. 3; and

Fig. 7 is a view taken on line 77 of Fig; 4. Referring now to thedrawings, I show an embodiment of my invention which preferably has apistolshaped main body portion A having a handle portion casting 5presenting a bore 7 having a liner. 8 defining an air inlet chamber 9.The liner 8 is merely to insure that air pressure will not rupture thehandle casting. if

the casting should be faulty, and' may be eliminated if desired. Thebottom end of this bore is enlarged and internally threaded tothreadedly receive a nipple 10, a

seal ring 11 being provided between the nipple and the handle. Thenipple has a threaded socket 15 for connecting the handle, as by aflexible hose not shown, to" a source of compressed, air, not shown. I

The upper part of the handle portion is provided with an internallythreaded, forwardly opening socket 17 into which the inner end 18a of acylinder 18 is threaded. A plug 20 has a reduced inner end portion 20athreaded into the internally threaded outer end portion of cylinder 18'.p

A guide member 25 has its hollow relatively large diameter inner endportion 25a threaded into an internally threaded socket 26 in the outerend of the plug, a lock nut 27 being employed to lock the guidemember tothe plug in various positions of axialadjus'tment to accommodate work.sheets'S of different thickness. The lock nut has a radial opening. 27ato receive a tool for rotating the'nut.

A'piston 30', having a seal ring 3021, is mounted to reciprocate in thecylinder 18, the piston having an,

outwardly opening e-nd recess 31', and having, an axial opening. 32. toslidably pass a tube 34 which has a pcripheral flange 35 presenting anannular shoulder 36 against which the piston abuts when in its innermostposition (Fig. 3) the flange being held against the inner end of thesocket by a screw' 3411. Tube 34 has an air inlet passageway 38 whichadmits air to the interior of the tool ahead of the piston for coolingpurposes and will be more'fully explained hereinafter and also forreturning the piston inwardly after the power stroke; The air enterstube 34 from chamber'9 through a passageway 40 in the handle, whichpassageway is controlled by a valve 42 actuated by a finger-operated.trigger 43 which is urged outwardly by spring 44, the outward movementof the trigger being restricted by a pin 45 disposed in a longitudinalslot 46 in the trigger. A seal. ring 47 is disposed between the tube 34'and piston 30 to prevent air from the chamberSG, behind the piston, frompassing around the tube. Chamber 50 is defined by' the inner end ofsocket 17, the inner end of piston 30' and the cylinder 18.

Air is admitted to chamber 50 from inlet chamber 9 through a passageway52, which is controlled by the valve 42. The latter valve has an axialpassageway 54', a radial passageway 53', a restricted radial bleed port55, and has a' transverse passageway 57 spaced forwardly from passageway53' and adapted to register with port 52' when the trigger 43 is pressedinwardly to actuate the piston. Inward movement of the valve closes thepassageway 40. 7

Plug 20 has an axial bore 60' in which a plu'ngerdl is mounted toreciprocate. The reduced inner end portion of the plunger carries a camdisk or washer 62 secured thereon by. a nut 63. The opposite end portionof the plunger has an enlarged diameter threaded portion 65 whichthreads into an internally threaded head member .66. Said head memberhas a rearwardly facing. annular shoulder 67 against which one end ofacoil spring; 68 bears, the opposite end of the spring bearing againstthe inner end of bore 26 in the plug. The hollow inner end portion ofguide member 25 provides a socket 69 in which head member 56reciproca'tes.

Guide member 25 has an axially outwardly extending, externally threaded,reduced diameter, tubular portion 25b .onto which is threaded a sleevememberZS'c as well as a punch member 70 having a frusto-conical outerend metal forming surface 71.

In use, I prefer to mount, on the periphery of the punch member and theportion 250, a sleeve-like electric heater, denoted in Fig. 3 by brokenline H. While there Letters Patent No. 2,740,035 to be well suited, thepurpose of the heater being to heat the metal work sheet S beingdimpled, by heat transfer through the punch mem ber 70. Sleeve member25c has a heat insulating chamber C. a a

A combination pilot pin and pull member 75 (which may be considered asan extension of plunger 61) has a headed inner end 76 disposed withinmember 66 and keyed portion 65 of the plunger by a key 78 to preventrelative rotation between those two members. The outer end portion ofthe pilot pin then extends outwardly through a bore 79 in punch member76 and axially through the forming surface 71, terminating in a projecting outer end portion for the reception of a die or second formingmember80 whose inner end presents a frustoconical forming surface 82conforming and opposed to the punch member 70.

Die member 80 comprises a housing 81 having an axial bore presenting arelatively large diameter portion 81a and a relatively small diameterportion 81b. Die portion 83 has a relatively large diameter end portion83a in which metal forming surface 82 is provided, and a relativelysmall diameter portion 83b which fits in the open end of bore portion811;, the annular shoulder 83c engaging the contiguous end of thehousing. Portion 83b is retained in the housing by means of radial pins84. Die member 83 has an axial bore 83d (see Fig. 6) which is coaxialwith the housing and the left hand end surface 83:: of member 83 isbeveled or flared whereby to provide an annular beveled cam surface.

A two-jawed collet 85 presents a beveled outer surface 8511 on the righthand end portion of each jaw, which surfaces conform to and carnminglyengage surface 832, the collet jaws being urged against surface 83a by acoil spring 86, a ring 87 being interposed between the spring and theannular shoulder 85b of the collet.

Pilot pin 75' has a flattened portion 75b (see Figs. 1, 3 and 6)adjacent its free end, the opposite sides of which flattened portionengage between the jaws of the collet. The rounded outer end of thepilot pin is first inserted through a hole S in the work sheet S andthence into the bore member 80 and thence between the jaws 85 of thecollet, the rounded left hand end of the pilot pin functioning to spreadthe collet jaws apart enabling the pilot pin to slide between the jawsuntil the flattened portion reaches a position between the jaws, atwhich time the jaws will, by virtue of the spring 86 and the cooperatingcam surfaces, snap into position against opposite surfaces of theflattened portion of the pilot pin, the opposed shoulders 75a (seeFig. 1) presented by the pilot pin at the ends of the flattened portion,engaging the ends of the collet jaws to prevent further axial movementof the pilot pin relative to the jaws in either direction. However, thepilot pin may be withdrawn from the member 80 by rotating the member 80relative to the pilot pin until the collet jaws engage the maximumdiameter portion of the pin, as shown in Fig. 6 at which time the pilotpin may be withdrawn axially from the die member or the die member maybe removed axially from the pilot pin as may be desired. To prevent thecollet from rotating relative to the housing, I provide, in the housing,radial pins 81c which extend inwardly to a limited extent between thecollet jaws.

Plunger 61 slidably and rotatably carries a cam disk 90 which abutsagainst the inner race 92 of a ball hearing member 93 whose outer race94 fits in an annular recess 95 in plug 20.

A plurality--preferably three in number, as best shown in Fig. 7ofcircumferentially spaced arms or levers 100 are pivotally connected tothe left or outer end of piston 30 adjacent its periphery by pivot pins101. While each of the arms may be generally described as beingL-shaped, each has a straight medial portion 100a, a radially andrearwardly disposed top end portion 1100b, and a rearwardly disposedbottom end portion 100:: whose curved 4 free end portion 160d engagesthe outer face of the cam disk 62.

In the idle position of the parts, as shown in Fig. 3, the outer or lefthand edge of each arm 100 bears against the recessed inner face of camdisk 90 approximately at the point of the curved intersection of armportions 109a and 10%.

Each of the members 250 and has a radial socket 105 for the reception ofa tool not shown, for the purpose of rotating said members relative tothe threads 25b for the purpose of screwing said members onto andunscrewing them from the threads 25b.

Member 25 has circumferentially spaced radial air bleed ports 107communicating with the socket 69, a

perforated sleeve 108 being mounted on the periphery of member 25 overthe outlet ends of the perforations. Those perforations are for thepurpose of discharging the cooling air which is introduced through thedevice through tube 34 during the idle position of the parts Operationof the device is as follows:

Commencing with the idle position illustrated in Fig. 3, the operatorinserts the outer end portion of the pilot pin through a previouslydrilled rivet or screw-receiving hole S in the work sheet S, holding thehandle 5 in one hand, the operator using his other hand to mount the diemember on the outer end of the pilot pin at the opposite side of thesheet. The operator then presses trigger 43 inwardly placing ports 54and 57 in communication with air passageway 52 leading from the inletchamber 9 into the cylinder 18 behind the piston 30. The air pressurethen moves the piston 30 outwardly or to the left, causing the arms orlevers 10!) to engage cam disk and thus to swing inwardly or to theright to cause their ends d to engage and push the cam washer 62 to theright, as shown in Fig. 4, thus pulling plunger 61 and pilot pin 75inwardly or to the right, causing the sheet to be embossed between theforming surface 82 of member 80 and the forming surface 71 of member 70.Ball bearing 92 allows carn disk 90 to rotate when engaged by arms 100,thus reducing the friction.

It will be observed that an annular flat surface 110,

perpendicular to the longitudinal axis of the tool, is pro.-

vided around the base of the frusto-conical forming portion 71, while alike flat annular surface 111 is provided around the forming surface 82in the forming member 80, the two flat surfaces being opposed to eachother. Thus, as the air pressure is applied to the chamber 50 incylinder 18, the tool is operated first to preliminarily fold the dimplebefore the flat surfaces around the hole 5' in the work sheet becomeclamped between the annular surfaces 110 and 11 1, after which the sheetbecomes clamped between those flat surfaces during the coining of thedimple between forming surfaces 71- and 82. When the trigger is releasedfrom its said inwardly pressed position, the air is restn'ctedlyreleased through the restricted bleed port 55 in valve 42 while port 40is opened to admit air through tube 34 to return the piston inwardly orto the right in cylinder 18. Y Inasmuch as the main body of the tooltends to becom heated by conduction from the heating element H, I provide for the constant passage of a stream of cooling air through port40, tube 3 and bore 69 around the plunger, and thence outwardly throughbleed ports 107 and per f-orated sleeve 108, so long as the valve is inthe position of Fig. 3.

I claim: l. A pressure applying tool comprising a body providing acylinder, a piston mounted to reciprocate in said cylinder, a pullplunger reciprocally carried :by said body and having its outer endportion projecting therefrom, said body having an outer end workengaging surface through which said outer end portion of said plungerextends, and means for moving said plunger inwardly of said body inresponse to movement of said piston in the opposite direction,comprising a cam member in said body surrounding the inner end portionof said plunger having thrust bearing against said body, acam disccarried by the inner end portion of said plunger in longitudinallyspaced opposed relationship to said cam member,

levers pivotally secured at their inner ends to said piston incircumferentially spaced relationship to each other; each of said levershaving an L-shaped outer end portion presenting portions engageablerespectively with said cam member and said cam disc in response tomovement of said piston in a direction outwardly of said body, and

' means for reciprocatingsaid piston; said piston, plunger,

cam member, cam disc, and said work engaging surface are coaxial withsaid body and wherein said levers are arranged symmetrical to saidplunger.

2. The tool of claim 1 which additionally includes a 7 work formingmember carried by the. outer end portion of said plunger inlongitudinally spaced opposed relationship as said work engaging surfaceof said body.

3. The tool of claim 1 in which said cam member is rotatable relative tosaid body and relative to said plunger.

References Cited in the file of this patent UNITED STATES PATENTS

